1. Field of the Invention
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method and apparatus for handling late version User Equipment (UE) category at an early release version network in a Long Term Evolution (LTE) system.
2. Description of the Related Art
Mobile communication systems developed to provide subscribers with voice communication services on the move. With the rapid advance of technologies, the mobile communication systems have evolved to support high speed data communication services as well as standard voice communication services. However, the resource shortage and user requirements for higher speed service in the current mobile communication system spurs the evolution to more advanced mobile communication system.
Recently, the next generation mobile communication system of the 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are being standardized. In order to fulfill the requirements of the next generation system standards, several schemes are under discussion such as one for reducing the number of nodes located in a communication path by simplifying a configuration of the network and another for maximally approximating radio protocols to radio channels.
Meanwhile, with the development of radio communication technologies, the mobile communication system evolves from an old version to a new version by adding newly introduced functions, resulting in a capability problem between the old and new networks.
For example, LTE has evolved from the initial version of Release-8 (Rel-8) to current version of Rel-10 with the intermediate version of Rel-9. However, such a communication environment where multiple networks running different versions of LTE standards coexist causes a problem in that the Rel-8/9 network does not understand ‘UE category’ signaled by a Rel-10 UE.
There is therefore a need of a method for resolving the compatibility problem between a UE and a network running different LTE versions.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.